(RALEIGH) -- An independent review last year found more than 200 cases where investigators with the state crime lab used improper practices during a 16-year period ending in 2003. Despite that, Attorney General Roy Cooper still doesn't think the state Bureau of Investigation should be separated from the crime lab.

Cooper says the lab has made significant changes and will soon be only one of two labs in the country with dual certification. He also ordered an audit of the lab, and says he's pleased with the progress that's been made.

Recently, the Senate unanimously voted for legislation that would clarify professional guidelines for forensic investigators in the SBI crime labs. The measure would also make it a felony for lab workers to intentionally withhold test results.